Honing stone apparatus

ABSTRACT

Honing apparatus including a head supporting a plurality of radially adjustable abrasive honing stones wherein the opening defined in the heads receiving the stones are of such configuration as to cooperate with retainers attached to the stones to maintain the stones in firm assembly with the head, as the stones are consumed. Oblique end faces defined at the ends of the head openings deform stone retainer leg portions adjacent, but spaced from, hone stone end surfaces, and as radial movement of the stone occurs the degree of deformation increases to maintain positive holding of the stone as its radial dimension decreases during use.

Jan. 16, 1973 c. H. KRAMM ETAL 3,711,260

HONING STONE APPARATUS Filed July 1, 1971 INVENTORS 52 W A W CARL H. KRAMM 1 ROGER E. 54 W @WJZMM/ FIG. 6

ATTORNEYS! United States Patent O M 3,711,260 HONING STONE APPARATUS Carl H. Kramm, Pinckney, and Roger E. Lee, Brighton, Mich., assignors to Wedge-Lock Honing Stone (10., Brighton, Mich.

Continuation-impart of application Ser. No. 54,403, July 13, 1970, now Patent No. 3,641,715. This application July 1, 1971, Ser. No. 158,908

Int. Cl. B24d 5/10, /00,' B24!) 9/02 U.S. Cl. 51204 8 Claims ABSTRACT OF THE DISCLOSURE Honing apparatus including a head supporting a plurality of radially adjustable abrasive honing stones wherein the openings defined in the heads receiving the stones are of such configuration as to cooperate with retainers attached to the stones to maintain the stones in firm assembly with the head, as the stones are consumed. Oblique end faces defined at the ends of the head openings deform stone retainer leg portions adjacent, but spaced from, bone stone end surfaces, and as radial movement of the stone occurs the degree of deformation increases to maintain positive holding of the stone as its radial dimension decreases dnring use.

CROSS-REFERENCES TO RELATED APPLICATIONS The instant application is a continuation-in-part of our copending application entitled Honing Apparatus, Ser. No. 54,403, filed July 13, '1970, now Pat. No. 3,641,715.

BACKGROUND OF THE INVENTION The invention pertains to the field of honing devices wherein a plurality of honing stones are mounted within a head, and are radially adjustable outward by means of an internal member in the form of a Wedge within the head and axially displaced therein.

A conventional hone construction utilized to accurately finish bores and cylinders includes a head having a plurality of radially disposed rectangular openings receiving abrasive stone bodies. Internally, the hone head includes an axially movable wedge which engages the inner surface of the stones, or stone body support, to adjust the stone body radially outward as it is consumed, and to maintain the outer surface of the abrasive stone body in engagement with the work with the proper degree of pressure.

In known hone constructions as the stone is consumed the radial dimension of the body decreases, and, with conventional stone body constructions, consuming of the stone increases the likelihood of the stone inadvertently escaping its opening in the hone head, which creates serious problems due to the possibility of damage to the workpiece, and also creates a safety hazard. Another disadvantage with conventional hone stone constructions lies in the necessity of discarding the stone long before all of the abrasive material has been consumed due to the 3,711,260 Patented Jan. 16, 1973 lem of retaining the abrasive stone body within the honing head, and such attempts are typified by disclosures shown in US. Pats. 3,037,333; 3,264,789 and 3,403,481.

Previously constructed hone stone body retainers have not overcome all of the disadvantages attendant with this type of tool, and prior stone constructions have been of such configuration that only a limited area of abrasive stone body is in engagement with the workpiece which increases the working time to produce a desired amount of workpiece metal removal.

SUMMARY OF THE INVENTION It is a basic object of the invention to provide a unique hone head and stone body assembly whereby high metal removing capacities may be achieved in a tool of relatively limited size, and yet the hone stone body may be positively retained within the head under all conditions of stone wear, and greater accuracies may be maintained with an increase in the effective usable life of hone stones.

In the practice of the invention a positive retaining relationship between the hone head and the hone stone body assembly is created by an overlapping and interlocking relationship between the surfaces defining the hone head opening and the components of the stone body retainer. As the stone body and retainer assembly is moved radially outward during use, the surfaces of the opening engaging the retainer deform the retainer in such a manner as to maintain, and even increase, the degree of frictional engagement between the stone retainer and the head, and thereby permit a greater portion of the stone to be utilized than is possible with conventional honing devices of this type.

In the practice of the invention the hone head includes a plurality of radially extending elongated openings of a rectangular configuration having a length substantially parallel to the axis of the head, and end faces defining the longitudinal ends of the opening. The end faces are obliquely related to the hone head axis in such a manner that the inner portions of the opening end faces are a greater distance from each other than the outer portions, i.e., the end faces are related in an outwardly converging direction. The hone stone body is also of a rectangular elongated configuration having lateral sides, an outer surface which constitutes the work surface, an inner surface disposed toward the head wedge actuator, and end surfaces substantially perpendicularly disposed to the stone body length. The stone body, itself, is of a 'wedge-like configuration due to the wedge configuration of the actuator, the radial dimension of the stone body being greater adjacent one end surface than at the other.

A metallic, nonferrous retainer is attached to the hone stone body, and includes a base portion of a planar configuration bonded to the stone body inner surface by a suitable adhesive. Leg portions of an initial fiat planar configuration extend radially outward from the base portion adjacent the stone body end surfaces, but slightly spaced therefrom wherein the dimension separating the leg portions adjacent the base portion is greater than the dimension separating the stone body end surfaces adjacent the body inner surface. Thus, the leg portions may be deformed inwardly toward the stone body.

Deformation of the retainer leg portions toward the stone body is facilitated by fold indentations defined in the retainer at the intersections of the base portion with the leg portions, and also defined in the surface of the leg portion of greatest radial length disposed toward the adjacent stone body end surface. Such indentations facilitate the bending and deformation of the leg portions in accord with the inventive concepts.

The dimensions of the head openings, and the stone and retainer assembly is such that the initial insertion of the stone and retainer assembly into an opening causes a deformation of the leg portions which serves to frictionally retain the stone and retainer within the head opening. As the hone is used, and the stones are consumed and radially displaced outwardly by the wedgetype actuator, the opening end faces, due to their oblique relationship, engage the leg portions forcing the leg portions inwardly toward the stone body to insure a continued high frictional engagement between the head and the stone and retainer assembly during radial movement thereof. The nonferrous nature of the retainer, which is preferably formed of brass, bronze or aluminum, or simi lar soft metal alloy, permits the retainer leg portions to be worn away by the workpiece as the stone body is consumed without scratching or otherwise defacing the workpiece surface being machined. The retainer construction is such as to occupy little space, and thus a relatively large stone may be employed in a head of relatively small size with the practice of the invention. This improved patio decreases machining time, which is of prime importance in high production metal finishing machines.

DESCRIPTION OF THE DRAWINGS 'I'he'aforernentioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein:

FIG. 1 is a detail, elevational, sectional view of a hone head and stone body and retainer assembly in accord with the invention illustrating the initial alignment of the head with a workpiece,

FIG. 2 is an enlarged, elevational, sectional view similar to FIG. 1 illustrating the details of the stone and retainer,

FIG. 3 is an elevational, sectional view similar to FIG. 2 illustrating the relationship of the components during use wherein the stone is partially consumed,

FIG. 4 is an elevational, sectional view similar to FIG. 3 illustrating the relationship of components when the stone body has been approximately half consumed during use,

FIG. 5 is a perspective view illustrating the stone body retainer prior to bending and assembly with a stone body, and

FIG. 6 is an elevational view of a stone body and formed retainer assembly prior to insertion into a honing head.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a honing head constructed in accord with the invention having new hone stone bodies inserted therein, and prior to the insertion of the head into the bore of the workpiece to be machined. In FIG. 1 the workpiece is indicated at 10 and includes a cylindrical bore 12 to be honed. The hone head 14 is of a cylindrical configuration having a hollow center 16 and a hollow shank 18 whreby the head is attached to conventional supporting and operating structure, not shown. A wedge are defined by longitudinally extending edge surfaces 28, and end faces 30 and 32. As is best appreciated from FIGS. 2 through 4, the end faces 30 and 32 are obliquely related to the surface 26 and the longitudinal axis of the head 14. The end faces are of a substantially fiat or planar configuration and the spacing between the end faces adjacent the hollow center 16 is greater than the spacing therebetween adjacent the exterior surface 26. Thus, the end faces 30 and 32 are disposed in an outwardly converging direction, and in actual practice the end faces depart from the vertical with respect to the relationship shown in FIGS. 2 through 4 by approximately 7% degrees.

The hone stone body and retainer assembly 34 is represented in FIG. 6. A hone stone body 36 itself consists of an abrasive material in the form of grains bonded together with a suitable bonder, usually in the form of a resin. The body 36 includes an outer surface 38, an inner surface 40, lateral side edges 42, and end surfaces 44 and 46. As will be appreciated from the drawing, the inner surface 40 is nonparallel with respect to the outer surface 38, and the departure from a parallel relationship is complementary to the angle of the wedge surface 22 whereby the outer surface 38 will be disposed substantially parallel to the head longitudinal axis, While the surface 49 is parallel to, and thus fully hacked and supported by the Wedge surface 22. This angular relationship between the surfaces 38 and 40 results in the radial dimension of the end surface 46 being greater than that of the end surface 44. In the disclosed embodiment the end surfaces 44 and 46 are substantially perpendicular to the outer surface 38.

The retainer for the stone body, as generally indicated at 48, is preferably formed of a strip of nonferrous, relatively soft material such as copper, bronze, aluminum or the like. The retainer 48, prior to forming, is of a configuration as illustrated in FIG. 5 including lateral sides St), a base portion 52, a large leg portion 54, and a smaller leg portion 56. Indentation or fold means are defined at 58 and 60 between the base portions, and such indentations are preferably defined by a stamping process. A linear fold indentation 62 is also defined in the leg portion 54 intermediate the intersection of fold indentation 60 and the leg portion free end 64.

When assembled to the stone body 36, the leg portions 54 and 56 are angularly disposed with respect to the base portion 52 as will be appreciated in FIG. 6. The fold indentations 58 and 6!! permit a sharp bend with respect to the leg portions and the base portion, and the leg portion 56 preferably defines an angle slightly less than with the base portion 52, while the leg portion 54 may be disposed at substantially 90 with respect to the base portion prior to insertion of the stone :body and retainer assembly 34 into a hone head openings 24.

The retainer 48 is fixed to the stone body 36 by an adhesive applied intermediate the stone body inner surface 40 and the base portion 52, and in this manner a permanent interconnection between the abrasive stone body and the retainer is achieved.

The length of the head opening 24, and the length of the stone and retainer assembly 34 is such that the abrasive stone assembly may be inserted into an opening 24 by first inserting,the leg portion 54 end into the deep portion of the opening and deforming the leg portion 54 toward the stone body 36 by engagement therewith by the end face 32. Thereupon, the end of the stone and retainer assembly 34 defined by the leg portion 56 may be inserted into the head opening adjacent end face 30 and a relationship such as illustrated in FIGS. 1 and 2 will occur.

It will be appreciated from the relationship of FIGS. 1 and 2 that the end face 30 is in substantially complete engagement with the leg portion 56, and the free end 66 of the leg portion is touching the end surface 44 adjacent the stone outer surface 33. However, a spacing exists between the free-end 64 of the leg portion54 and the end surface 46. Of course, the fact that the spacing between the legpOrtins 54 and 56 adjacent the base portion 52 is greater than the spacing between the end surfaces 44 and 46 adjacent the-inner surface 40 permits the desired inward deflection of the leg portions, and the inherent resiliency of the metal of the leg portions aids in maintaining the initial engagement of the stone and retainer assembly within the head opening.

With a new honing stone assembly 34 the wedge actuator 20 will be shifted to the right, FIGS. 1 and 2, in order that the stone surface 38 will be in substantial alignment with the head surface 26 and only project slightly beyond the hone exterior surface.

The fact that the end faces 30 and 32 are obliquely disposed defines an undercut which, in conjunction with the deflection and close fit relative to the leg portions 54 and 56 creates an effective means for holding a new stone and retainer assembly 34 in the associated head opening 24. The head 14 is inserted in the workpiece bore 12 and the workpiece and head are relatively rotated or oscillated, and as the stone is gradually consumed, the wedge 20 is moved to the left to maintain a firm pressure between the stone outer surface and the workpiece bore. As appreciated in FIG. 3, wherein a portion of the stone has been consumed, the engagement between the leg portion 54 and the end face 32 causes the leg portion to deform inwardly, the primary bending occurring at the indentation 62. Also, as the stone is moved outwardly during use the end face 30 will maintain engagement with the leg portion 56 whereby a firm frictional engagement between the end face and the retainer leg portions exist during all phases of operation, thereby producing an effective holding grip between the stone assembly and the head.

As the wear on the hone stone 36 continues the leg portion relationship with respect to the head opening end faces is similar to that shown in FIG. 4. As the base portion 52 approaches end faces 30 and 32 the degree of deformation of the leg portions toward the stone body 36 increases, and the free end 64 of the leg portion 54 approaches, and may engage the stone end surface 46. Thus, even though the radial dimension of the stone as defined by the distance separating the surfaces 38 and 40 reduces, an effective holding relationship between the head and the stone and retainer assembly is maintained.

As will be appreciated from the drawings, the free ends 64 and 66 of the leg portions engage the workpiece bore 12. However, due to the soft and nonferrous nature of the material of the leg portions, scoring or scratching of the workpiece does not occur in that the workpiece is usually of steel, and thus considerably harder than the material of the retainer.

When it is desired to remove the worn stone from the associated head opening 24 the installation procedure is reversed, the leg portion 56 being first lifted from the opening 24 and once the leg portion 56 clears the end face 30 the stone may be easily withdrawn from the opening. Usually, a clearance exists between the free end 64 of the leg portion 54 and the stone end surface 46, and

this clearance aids in shifting the stone and retainer assembly to the left slightly to facilitate removal.

It will be appreciated that in the practice of the invention a firm and efiicient holding relationship between the honing head opening and the stone and retainer assembly is maintained throughout the life of the stone body, and the invention eliminates the previous troublesome occurrence of the stone body dropping or falling from the honing head opening. In that, except for the cross-sectional area of the leg portions 54 and 56, the opening 24 is completely occupied by the abrasive outer surface 38, and a most efiicient relationship is established between the size of the openings 24 and the effective abrasive area of the hone stone contained therein, resulting in a very efficient and rapid cutting hone head for a given size head.

Various modifications to the inventive concept may be apparent to those skilled in the art without departing from the spirit and scope of the invention.

We claim:

1. A hone stone and head assembly comprising, in combination, an elongated honing head having an axis, a hollow center, an annular wall and an exterior surface, at least one radially extending elongated rectangular opening defined in said head wall intersecting said hollow center and said exterior surface, said opening including end faces defining the opening length, said end faces being obliquely related to each other in a converging direction from said hollow center to said exterior surface, an abrasive stone body of an elongated configuration received within said opening, said body including a longitudinal axis, lateral sides, an outer surface, an inner surface and first and second end surfaces, said end surfaces being transversely disposed to said body axis, a retainer attached to said stone body, said retainer including a base portion afiixed to said stone body inner surface and deformable first and second leg portions extending from said base portion in adjacent relationship to said stone body end surfaces, the spacing between said leg portions at said base portions being greater than the distance between said stone end surfaces adjacent said inner surface, said leg portions engaging said opening end faces and said end faces deforming said leg portions toward said stone body upon radial outward movement of said stone body and retainer through said opening, and stone body and retainer actuating means within said head hollow center selectively radially moving said stone body and retainer outwardly through said opening.

2. In a hone stone and head assembly as in claim 1 wherein said retainer is formed of a relatively soft nonferrous metal.

3. In a bone stone and head assembly as in claim 1 wherein said first stone end surface is of greater radial dimension than said second end surface, said first leg portion including an inner surface disposed toward said first stone end surface and fold forming means defined in said leg portion inner surface spaced from said retainer base portion.

4. In a hone stone and head assembly as in claim 3 wherein said fold forming means comprises a linear indentation defined in said first inner surface substantially parallel to said stone inner surface and retainer base portion.

5. A hone stone assembly for use with honing heads having rectangular stone receiving openings and an internal stone support and expander comprising, in combination, an abrasive stone body of an elongated configuration having first and second ends, lateral sides, an outer surface and an inner surface, a retainer attached to said body, said retainer including a base portion attached to said body inner surface and first and second deformable leg portions extending from said base portion disposed adjacent said body first and second ends, respectively, the spacing between said leg portions adjacent said base portion being greater than the spacing between said stone body ends whereby the free ends of said leg portions may be deflected inwardly toward said body.

6. In a hone stone and head assembly as in claim 5 wherein said retainer is formed of a relatively soft nonferrous metal.

7. In a bone stone and head assembly as in claim 5 wherein said first stone end surface is of greater radial dimension than said second end surface, said first leg portion including an inner surface disposed toward said first stone end surface and fold forming means defined in said inner surface spaced from said retainer base portion.

8. In a hone stone and head assembly as in claim 7 wherein said fold forming means comprises a linear inden- 7 8 bation defined in said first inner surfiace substantially 3,109,266 11/1963 -Eng1e 51--346 parallel to said stone inner surface and retainer base por- 3,154,893 11/1964- Greenberg et 211. 51338 X tion. 3,403,481 10/ 1968 McDonald 51-338 References Cited UNITED STATES PATENTS 5 OTHELL SIMPSON, Prlmary Exammer 2,952,952 9/1960 Stanhope 51204 US. Cl. X.R. I

2,991,597 7/1961 Calvert 51204 51,33 8 

